Universal Coins Mod 1.12 exchanges almost any item using coins. The coins come in five values: the Coin (value 1), the Coin Stack (value 9), the Large Coin Stack (value 81), the Small Coin Bag (value 729), and the Coin Bag (value 6561). 9 of a lower tier will get you 1 of the higher tier; also 1 of a higher tier will get you 9 of the lower tier.